Everything has its price, and in the current buoyant art market, everyone seems more than willing to sell. With auction records at vertiginous highs, many institutions have rushed to profit. So when Thomas Jefferson University, a medical school in Philadelphia, decided to sell its prized Thomas Eakins painting through a Christie's private sale, they expected a straightforward, profitable, $68m deal.

That is, a deal that wouldn't rouse British-style patrimonial ire, which is precisely what it has done. Turns out one thing that can't be bought is the mixture of national pride and cultural fervour so common on the European side of the pond. This time it's a dusty US institution that has become mired in the court of public opinion.

Earlier this month, the university's board agreed to sell Eakins's 1876 masterpiece The Gross Clinic, arguably one of the most iconic American paintings, to a consortium of the National Gallery of Art in Washington and the future Crystal Bridges Museum of American Art, funded by the largesse of Wal-Mart heiress, Alice L Walton. Part of the agreement included a clause to allow local institutions and government bodies a 45-day period to match the offer - a good faith clause perhaps hinting that a backlash might be on the way.

The whopping sum offered for the painting is the highest price ever paid for a work by the portraitist and Philadelphia native - in fact twelve times the auction record - as well as for any 19th-century American painting. The timing was not coincidental. Prices for such paintings are soaring, spurred by the resurgent interest of billionaire collectors for American-inflected works such as Eakins' sculling paintings.

But the sale plans have drawn fire, in protest at the university's blatant philistinism. The painting has been its property, and that of Philadelphia, since being purchased by alumni in 1878 (for $200). To add to the hometown fervour, Eakins himself was born, lived, and worked in Philadelphia, where his subject, Dr Samuel Gross, was also an eminent surgeon and professor.

Several institutions are now putting together campaigns to raise a counteroffer, including the Philadelphia Museum of Art and the Pennsylvania Academy of Fine Arts. Philadelphia mayor John F. Street has also proposed deeming the painting a "historic object" under the city's preservation ordinances - a ploy to buy some fund-raising time.

The beleaguered university is accusing the city of trying to exert control over its property in retort - thereby missing to acknowledge the genuine feeling that's sparked the debate in the first place. The catch is: if the painting is deemed "historic", the university could still sell it, but its sale would be subject to the explicit approval of something called the Philadelphia Historical Commission.

Hearings on the matter are scheduled for next month. This being the States, an all-out legal brawl is surely on the way.